{
  "abstract": "Future quantum communication infrastructures will need to serve heterogeneous users on shared physical channels: short-range, high-throughput links favor Continuous-Variable Quantum Key Distribution (CV-QKD), while long-reach, high-loss links remain the domain of Discrete-Variable QKD (DV-QKD). Wavelength-division multiplexing (WDM) of the two protocols on a common channel would address both regimes simultaneously, but their markedly different noise sensitivities make coexistence non-trivial and, to date, experimentally untested. Here we report the first simultaneous operation of two independent CV-and DV-QKD systems on a common optical channel, using standard C-band DWDM filters at 1550.12 nm (CV) and 1545.32 nm (DV). We demonstrate joint operation on both optical fiber and a 620 m urban daylight free-space link. On fiber, the two systems exhibit the expected complementarity, crossing over at 7.56 dB of channel loss where both deliver ∼1.43 Mbit/s; in daylight free-space, both sustain Mbit/s key rates under time-varying atmospheric attenuation. Across all configurations we observe no measurable multiplexing-induced penalty in QBER or excess noise. These results establish hybrid CV-DV WDM as a practical building block for heterogeneous quantum communication networks, where metropolitan high-throughput users and long-reach backbone links can be served on a single physical infrastructure.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.19745",
  "author_total": 10,
  "authors": [
    {
      "name": "Mattia Sabatini"
    },
    {
      "name": "Edoardo Rossi"
    },
    {
      "name": "Matías R. Bolaños"
    },
    {
      "name": "Francesco Vedovato"
    },
    {
      "name": "Thomas Liege"
    },
    {
      "name": "Eleni Diamanti"
    },
    {
      "name": "Giuseppe Vallone"
    },
    {
      "name": "Paolo Villoresi"
    },
    {
      "name": "Yoann Piétri"
    },
    {
      "name": "Marco Avesani"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bmyt8sjyj0nkm.bib",
  "cited_by": 0,
  "doi": null,
  "fulltext_url": null,
  "id": "bmyt8sjyj0nkm",
  "issns": [],
  "landing_url": "https://hal.science/hal-05738344v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.qphy"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://hal.science/hal-05738344/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bmyt8sjyj0nkm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:27Z",
      "native_id": "hal-05738344",
      "source": "hal",
      "url": "https://hal.science/hal-05738344v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "hal:1.phys.qphy",
      "subfield": "quantum"
    }
  ],
  "title": "Multiplexing of Continuous-Variable and Discrete-Variable Quantum Key Distribution Systems over Fibered and Free-Space Channels",
  "title_text": "Multiplexing of Continuous-Variable and Discrete-Variable Quantum Key Distribution Systems over Fibered and Free-Space Channels",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:27Z",
  "url": "https://research.draconitic.com/paper/bmyt8sjyj0nkm",
  "venue": "HAL",
  "versions": []
}